SEA GRANT COLLEGES 207 



fossils in bottom sediments, for this not only extends our knewledge of the 

 distribution of fish beyond their areas of spawning but yields information on 

 the history of peristancy, fluctuations, and competition of fish stocks. Thus at 

 its outset a fishery can proceed with vital knowledge of the history of the fish, 

 and, through a study of the associated microfossils, a knowledge of the organic, 

 oceanic, and meteorological condition under which it has thrived or declined. 



Under rather rare conditions along coasts sediments are deposited rapidly 

 and are not subsequently disturbed. Thus the record of fishes, the oceanography 

 and something of the meteorology can be read in calendar pages of a few years or 

 so for several thousand years. 



The implications of a broad survey exploiting this entry into the record of the 

 oceans of this world are very great. 



{(I) Plankton collections. — Much is known about the distribution of plankton 

 in rather limited regions of the world oceans. A much broader understanding is 

 essential to the evaluation of the planet's productivity, of potential fisheries, and, 

 of course, to the full significance of research into circulation and the oceano- 

 graphic changes recorded in the recent past as discussed above. 



II. APPRAISAL OF THE OVERALL NATURAL CONSTRAINTS, LIMITS, AND OPPORTUNITIES OF 



OCEAN USE 



Specific projects for utilization of the oceans can be profitably approached on 

 and ad hoc basis. For example, a new fishery, a tidal powerplant, a disposal 

 area for nuclear waste, or etc. can be established on the basis of regional investi- 

 gations and the resultant understanding. 



However, the significance of the oceans to the needs of the world's human 

 population is best compreliended not by a multiplicity of local studies, but rather 

 by an evaluation of the planetary potential, its constraints, its limits, and its 

 opportunities. 



Altiiough data for such approaches are in some cases scanty, enough exists 

 for us to set significant limits, adequate for long-term guidance. As further data 

 are available these overall approaches can be perfected. 

 As examples I can quote the results of studies that show : 



{a) Oceanic evaporation and the resultant land precipitation is a suffi- 

 cient rainfall for the optimum terrestrial agriculture for some 40 times the 

 world's present population. 



(&) The total tidal power in the world's oceans is less than 10 percent of 

 the expected human power needs at the onset of the 21st century, with the 

 available tidal power much less than this. 



(c) Outside of the nuclear power resources, the greatest single utilizable 

 energy reservoir on this earth is that represented by the temperature 

 gradient of the ocean. This giant low-level reservoir exceeds the total esti- 

 mated fossil fuel reserves of earth. 



id) The capacity of the oceans to receive nuclear waste is saich that a 

 distributed input of about 100 tons of mixed fission products annually would 

 give rise to acceptable levels of radioactivity in marine foods. This input 

 represents about 10 percent of the estimated human electrical power require- 

 ments in the year 2100. 



(e) The common fisheries of the oceans are ultimately capable of supplying 

 the total protein needs of a world population that is somewhat greater than 

 at present. They are capable of supplying the animal protein require- 

 ments for a population of 60 billion people. 



A harvest concentrating on the herbivores in the sea could supply an order 

 of magnitude greater yield. 



(/) It can be shown that, because of their dilution and microscopic 

 dimensions, the primary food materials of the sea can probably never be 

 profitably harvested by methods involving the input of energy from external 

 sources (such as nuclear or fossil fuel power) for pumping, straining, etc. 

 Thus such primary harvest must use sources of energy contained in the 

 ocean, such as ocean currents, the motion of organisms, or the activity of 

 filter-feeding creatures. 



Ocean "farming," as the analog to terrestrial farming, as a consequence 

 will be restricted to special limited regions of the sea such as bays or coral 

 lagoons. The general harvest of the oceans productivity in the ultimate is 

 constrained to methods paralleling terrestrial "ranching" and grazing, where 

 a preferred herl)ivore is sent to range (if a filter-feeding fish), or cultural 

 on artificial substrata (if it is an attaclied filter-feeding organism, like a 



